AppInsightsTraceWarning

Repro app for Azure bug with Trace warning:

AI: TelemetryChannel found a telemetry item without an InstrumentationKey. This is a required field and must be set in either your config file or at application startup.

See: microsoft/ApplicationInsights-dotnet#2070

Steps:

1. Change ConnectionString in appsettings.json
2. Build Docker image: docker build --pull -t appinsightstracewarning -f .\AppInsightsTraceWarning\Dockerfile .
3. Tag and push your Docker image:
   1. docker tag appinsightstracewarning your_container_registry.azurecr.io/appinsightstracewarning
   2. docker push your_container_registry.azurecr.io/appinsightstracewarning
4. Deploy new App Service with Docker image on Azure
5. Every ~15 minutes you will see trace warning in your App Insights